Iran has a recently acquired choke hold on the world economy.
There is no need to document why.
Except that part of "why" has given Iran a valuable new revenue stream: The Iran/Oman Strait of Hormuz Authority charges a toll for every ship going through the Strait.
Iran doesn't have to worry much about donnie doing any real damage for several years because he will have to mete out only tiny tantrums just to make himself feel good, because, if he throws a really big tantrum there are only enough weapons left for that big one; then all is silent on the Iranian front.
Here's where China and Russia are really paying attention: the only way to let donnie do multiple big tantrums in Iran would be to ship all the offensive and defensive weapons currently dedicated to Continental United States and the Western Pacific to the Middle East; if that happens China can give pretty serious thought to taking Taiwan and Russia can give pretty serious thought to taking the Balkans and Poland; trump has destroyed NATO and in, any event, a counterattack from NATO on a Russian incursion to the Balts would make an all-out nuclear counter-attack on the United States by Russia a good gamble, what with all America's defenses being in the Middle East.
Iran can attack the Gulf States whenever they want to with little threat of reciprocal damage: the Gulf States don't have many US supplied defense devices left either, and the US is in charge of offense so Iran, who is massively ramping up offensive missile production (you might think that donnie just needs to blow all of that up; see paragraph four, above to find out why he can't do that) and making significant improvement to those devices, such as making them wiggle course at the last minute of descent making it harder for defensive missiles to hit them and making it therefore necessary to use more defensive missiles for each incoming offensive missile, defensive missiles that are in very short supply just like the offensive ones.
Iran knows that as long as donnie can't get out of his war - a war with which he no weapons to fight - they can keep working him for concessions for them to come back to the table and talk to him, without ever really having to come back to the table; they recently said minimum acceptable starting point is signing the previously abandoned MOU; then they would think about talking to Art of the Deal Guy about their deal.
Looks checkmate without ever touching the king.
Looks even more like The Art of the Schlemiel.
